Just a thought, I’d have to see one first!
Another idea for the Garage door detector. It is PROBALLY using a mercury switch inside the transmitter to detect the angle of the door. Replace this with a photocell to detect light instead. Mount one in up to three of the rooms that you have a tendency of leaving the lights on in. This will indicate to you that you have left the light on and you can shut it off.

Chris Couture